Private data were changed in the code.

gistfile1.txt

<?php
/**
 * Author: Egor N. Kostyuk
 * Date: 06.02.2018
 * Time: 15:35
 */

if (!defined('ABSPATH')) {
    exit;
}

if (!class_exists('EJ_WC_Email_New_Order_Notification_To_Regional_Office_and_To_Additional_email')) :

    class EJ_WC_Email_New_Order_Notification_To_Regional_Office_and_To_Additional_email extends WC_Email_New_Order
    {

        private $warehouseNamesInMinskRegion = [
            'machulishhi', 'shabany', 'minsk-center'
        ];
        const ADDITIONAL_EMAIL = 'test1@example.by,test2@example.by';

        public function __construct()
        {

            $this->id = 'new_order_regional';
            $this->title = 'New order regional';
            $this->description = 'New order email notification for regional managers';

            parent::__construct();

            $isOrderToMinskOffice = $this->isOrderToMinskOffices();

            // Set regional and additional emails
            $regionalEmail = WC()->session->get('order_regional_email_for_notification', NULL);

            if (check_wholesale_user()) {
                $manager_email  = get_user_meta(get_current_user_id(), 'wwlc_cf_email_manager');
                if(count($manager_email) > 0) {
                    $this->recipient = $manager_email[0];
                } else {
                    $this->recipient = self::ADDITIONAL_EMAIL;
                }
            } else {
                if (is_null($regionalEmail)) {
                    if ($isOrderToMinskOffice) {
                        $this->recipient = self::ADDITIONAL_EMAIL;
                    } else {
                        // This email class have to off if regional and additional emails isn't defined
                        // (or isn't needed).
                        $this->enabled = false;
                    }
                } else {
                    $this->recipient = $isOrderToMinskOffice ? self::ADDITIONAL_EMAIL : $regionalEmail;
                }
            }



        }
        
        //Check order to Minsk offices
        protected function isOrderToMinskOffices()
        {
            $regionalWarehouseName = WC()->session->get('order_regional_warehouse_name_for_notification', NULL);
            if (is_null($regionalWarehouseName)) {
                return false;
            } else {
                if (in_array($regionalWarehouseName, $this->warehouseNamesInMinskRegion)) {
                    return true;
                } else {
                    return false;
                }
            }
        }

    }

endif;

return new EJ_WC_Email_New_Order_Notification_To_Regional_Office_and_To_Additional_email();